The implementation relies on custom mime-type specified in .ui files.
However, the strings weren't marked as non-translatable, so language
teams that decided to translate application/x-amarok-tag-token effectively
broke drag & drop for their users. (the blame goes to Amarok team, of
course)

Myriam, more than 2-year-old bug fixed in a couple of hours, don't you
like your GSoC student? :-)